Entreprise française de cybersécurité depuis 2004
☎ 03 60 47 09 81 - info@securiteinfo.com
☎ 03 60 47 09 81 - info@securiteinfo.com
In the Linux kernel, the following vulnerability has been resolved:drivers: staging: rtl8723bs: Fix deadlock in rtw_surveydone_event_callback()There is a deadlock in rtw_surveydone_event_callback(),which is shown below: (Thread 1) | (Thread 2) | _set_timer()rtw_surveydone_event_callback()| mod_timer() spin_lock_bh() //(1) | (wait a time) ... | rtw_scan_timeout_handler() del_timer_sync() | spin_lock_bh() //(2) (wait timer to stop) | ...We hold pmlmepriv->lock in position (1) of thread 1 and usedel_timer_sync() to wait timer to stop, but timer handleralso need pmlmepriv->lock in position (2) of thread 2.As a result, rtw_surveydone_event_callback() will block forever.This patch extracts del_timer_sync() from the protection ofspin_lock_bh(), which could let timer handler to obtainthe needed lock. What`s more, we change spin_lock_bh() inrtw_scan_timeout_handler() to spin_lock_irq(). Otherwise,spin_lock_bh() will also cause deadlock() in timer handler.
No PoCs from references.
- https://github.com/w4zu/Debian_security